WR 250/426 power


Apr 30, 2001
Check this: Everybody has heard about retiming the exhaust cam on our WR's. I finally got off my butt and did it. It took me less than 45 min.,including cleaning everthing BEFORE taking it apart. As I expected the bottom was a little softer as well as the mid hit, but a big increase in top end pull. I happened on a thread WRooster posted relating to 250 midrange bog,so I disconnected the same grey wire to the black box. Guess what boys and girls? I have as much or more bottom,major mid and silly YZ top end power. The front wheel lifts in 4th like it used to in 2nd.I haven't even sorted jets yet because i've got a vortip on the way. DO THIS NOW! you will really enjoy your bike afterward. Thanks to everbody for your posts!:cool


Jun 10, 2001
Gotta agree whole hog w/you on the cam change deal.I just did it this weekend- It's worth it, w/out regret. I'm coming off of a YZ 400, so I've been ridin' the 250 hard-on the top of the power band. Now I've got more,with a harder hit. Coupled w/the wider gearbox, I feel like I've got a leg up in ridability on the YZ mounted guys.
Tell me more on the grey wire deal-I'm new here @ this forum. What did it do, and why does it help ?


Jun 10, 2001
Originally posted by wrooster
for details on the wr250f "gray wire" mod, see
look for the DRN thumper forum thread titled "attn '01 wr250f owners"

the wrooster
Like "oh my gawd, it's a TOTALLY diff bike" Many thanks on the link to Thumper Central. I stayed up waaay past my bedtime reading all the stories and tests on the "grey wire " issue. I made the free, yes,free, way FREE mod on the scoot today, and oh my.... I've already said that. This is so cool. These guys searched and dug and found the problem and fixed it, tested it ,etc. What a great group of guys...but anyone who does the dirt is, right ?
Many thanks for the reply, the link, and the MOD. I kinda like my that she's been ENHANCED! thanks again wrooster

Dec 29, 2000
Greg wire trick

Just returned from motocross track and now the WR250 pulls hard in the mid range. I was able to stay in 3rd in two sections where I used to downshift, plus she really gets to the top quickly. This is probably the only mod most will
need. Falling in love again is euphoric!
Feb 12, 2001
only mod you need? naaahhh

yep, it's like getting a new bike all over again!

so, to date, the wr250f crowd has in it's bag-o-tricks...

a) remove airbox cover and snorkel
b) trim throttle stop to the yzf spec
c) uncork exhaust (and get a Vortip for when you need stealth)
d) change to yz timing
e) cut the now-famous-you-will-read-about-it-next-month-in-dirt-bike-mag grey wire.
f) due to all of the above, and especially if you ride at low altitudes, you *may* have to go one notch richer on the needle to compensate for the better breathing and more aggressive exhaust cam setup.

if you aren't excited now, well, up the voltage when you go for your weekly electro-shock therapy.

the wrooster
'01 yama wr250f